Mycophenolic acid
At a Glance
Why Get Tested?
To determine the concentration of mycophenolic acid in the blood in order to monitor levels and prevent toxicity
When to Get Tested?
As soon as mycophenolic acid therapy begins and whenever the dose is changed; may be ordered frequently at first, then at regular intervals; whenever excess or deficient levels of mycophenolic acid are suspected
Sample Required?
A blood sample drawn from a vein in your arm
Test Preparation Needed?
None
The Test Sample
What is being tested?
This test measures the amount of mycophenolic acid in the blood. Mycophenolic acid is the active metabolite of mycophenolate, a drug that is primarily given to patients who have had a heart, kidney or liver transplant. There are two formulations of the drug available, mycophenolate mofetil and mycophenolate sodium.
Mycophenolic acid belongs to a group of immunosuppressant drugs which helps to prevent organ rejection. Normally, a person’s immune system would recognise a transplanted organ as foreign and begin to attack it. Mycophenolic acid limits this response by preventing the activation of the immune system cells known as T-lymphocyte and B-lymphocytes.
Like other immunosuppressant agents, mycophenolic acid may cause side effects and adverse reactions and is associated with an increased risk of infection and the development of lymphoma and other cancerous conditions,especially skin cancers.
Mycophenolate is given to organ transplant patients in conjunction with other immunosuppressant drugs, such as cyclosporin and tacrolimus.
The mycophenolic acid blood test is usually measured as a “trough” level, that is, the blood sample is taken just before the next dose of the medicine is due, when the drug is at its lowest concentration in the blood.
How is the sample collected for testing?
A blood sample is obtained by inserting a needle into a vein in the arm.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
The Test
How is it used?
The mycophenolic acid test is ordered to measure the level of drug in the blood. This test has not always been done routinely in people taking mycophenolic acid. Instead, doctors give a standard dose of mycophenolic acid and monitor the drug level indirectly by observing the effects on the patient. However, the physician may also wish to monitor the drug level directly by measuring the level of mycophenolic acid in the blood. For example, they may be concerned that the standard dose may be too high or too low because the mycophenolic acid level may be affected by another medicine the person is taking.
If someone is taking mycophenolate in addition to cyclosporin or tacrolimus, then both MPA and the other immunosuppressant concentrations will be measured.
Since mycophenolic acid can lower white blood cell counts and cause anaemia, a full blood count (FBC) will frequently be ordered along with the mycophenolic acid test to evaluate the body’s blood cell status. Other tests may also be periodically ordered to evaluate organ function as MPAmycophenolic acid levels can be affected by changes in kidney and liver function.
When is it requested?
Mycophenolic acid test and FBC are ordered frequently at the start of therapy and then at intervals for as long as the patient is taking mycophenolate. The mycophenolic acid test may be performed whenever there is a change in dosage, a change in other medications that the patient is taking, or whenever a patient has symptoms that suggest side effects, toxicity or organ rejection.
What does the test result mean?
Concentrations that are too high may cause toxicity. Concentrations that are too low may lead to rejection of the transplanted organ.
If the person is also taking another immunosuppressant and/or other medications, then all of them will need to be in balance. Patients should work closely with their doctor and transplant team.
Is there anything else I should know?
Mycophenolic acid levels can be affected by other medications. Drugs that reduce mycophenolic acid concentrations include antacids and cholestyramine. Drugs that can increase mycophenolic acid include ganciclovir, probenecid, and acyclovir. Herbal supplements may interact with mycophenolic acid.
Mycophenolic acid can decrease the effectiveness of oral contraceptives, and has been linked with first trimester miscarriages and congenital birth defects. Women should not become pregnant while taking mycophenolate and should not breastfeed. Two forms of birth control are recommended, as is a pregnancy test prior to the start of the medication. Patients who become pregnant should talk to their doctor about the associated risks.
Those who are taking mycophenolic acid should talk to their doctor before getting any vaccines.
Patients may have side effects and experience complications such as infections and slow healing even when taking mycophenolic acid properly. Side effects may include:
Common Questions
Ask a Laboratory Scientist
Related Pages
On This Site
Conditions: Autoimmune disorders, lymphoma, anaemia
Elsewhere On The Web
Kidney Health Australia: Kidney Transplantation
American Society of Transplantation: Patient Education Brochures
Medicines for Keeping Your New Heart or Lung Healthy
Medicines for Keeping Your New Kidney Healthy
Article Sources
NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.
